Obsessive compulsive disorder (OCD) is a chronic, relapsing psychiatric affliction with a lifetime prevalence of 1-3%. According to the Diagnostic and Statistical Manual of Mental Disorders (4th ed; DSM IV), the essential features of this disease are recurrent obsessions and/or compulsions (e.g., doubting, checking, washing) that are time consuming (i.e., they take more than 1 hour a day) or cause marked distress or significant impairment.
The most effective treatments for mental disorders like OCD are antipsychotic and behavioural treatments. Yet, around 30% of the patients are refractory to pharmaco- and behavioural therapy. In addition, side effects such as agranulocytosis (loss of the white blood cells that help a person fight infection) and changes in a person's metabolism (leading to diabetes) are serious problems that limit the use of these drugs. There is therefore a need in the art for a therapy for such diseases that does not have these unwanted side effects.